This application relates to a new re-usable tube for winding fiberglass yarn, particularly in the initial yarn formation stage. That yarn formation process is described in U.S. Pat. No. 3,910,513 to Gelin, et al. and those of ordinary skill in the art are familiar with the process described therein. Gelin discloses that the yarn (also referred to as a roving at this stage) starts out as molten glass. It is drawn through bushings into fine strands that are then cooled by water and wound on a tube mounted on a collet. Once the package of yarn on the tube has been completely wound on a collet, the tube can be removed from the collet and is internally collapsible to a reduced diameter so it can be withdrawn from the core of the package, leaving only the package or “cheese” of fiberglass yarn or roving. These packages typically weight about 45 pounds and during the winding process can rotate as fast as 4500 rpm. These conditions put stresses on the tube the yarn is wound on and require reliable tube performance. In many cases the package is further treated after the package is complete and before the tube is removed.
U.S. Pat. No. 6,719,242 to Floyd et al. describes subsequent processing of the newly-formed yarn to drive off aqueous or other solvents from a finish applied to the yarn. This heat treating is described by Floyd et al. as including exposing the yarn on its winding tube to temperatures as high as 400 degrees Fahrenheit. In practice, however, temperatures more typically top out at 300-310 degrees Fahrenheit. Nonetheless, such temperatures are extreme enough to cause gradual degradation of the tube as it undergoes numerous reuses. The disclosures of the Gelin et al. and Floyd et al. patents are incorporated herein by reference.
The conventional tubes, which are commonly made of layers of paper, fail prematurely, requiring their replacement. Some tubes incorporate Tyvek fabrics of man-made fibers and filaments suitable for making into household furnishings and apparel and for industrial uses. Various attempts have been made to improve the longevity of the tubes, but often encounter other drawbacks, particularly arising from the differential thermal expansion of the layers of the tube that put stresses on the tube to make the tube fail early or otherwise fail as successful tubes for holding the yarn in place to make a the cheese or package that producers desire.